The present invention relates to a sheet film package and a buffer sheet member, and more particularly to a sheet film package for loading a plurality of sheet films sealed in a flexible bag-shaped light-shielding member into an image recorder or the like and for allowing the sheet films to be smoothly delivered or fed in a prescribed direction, and also to a buffer sheet member for preventing the sheet films in the sheet film package from having pressure marks.
Radiation image films are generally used in the medical field for recording radiation images of objects such as human bodies with an X ray for medical diagnosis. For photographing an object on such a radiation image film, it has been customary to load the film into a radiation image photographing device under a light-shielded environment and expose the emulsion layer of the film directly to an X ray having passed through the object for recording the image of the object thereon.
There has recently been developed and widely used, particularly in the medical field, a radiation image recording and reproducing system for producing the radiation-transmitted image of an object using a stimulable phosphor material capable of emitting light upon exposure to stimulating rays. When a certain phosphor is exposed to a radiation such as X-rays,.alpha.21 -rays, .beta.-rays, .gamma.-rays, cathode rays, or ultraviolet rays, the phosphor stores a part of the energy of the radiation. When the phosphor exposed to the radiation is subsequently exposed to stimulating rays such as visible light, the phosphor emits light in proportion to the stored energy of the radiation. The phosphor exhibiting such a property is referred to as a "stimulable phosphor".
In the radiation image recording and reproducing system employing such a stimulable phosphor, the radiation image information of an object such as a human body is stored in a sheet having a layer of stimulable phosphor, and then the stimulable phosphor sheet is scanned with stimulating rays such as a laser beam to cause the stimulable phosphor sheet to emit light representative of the radiation image. The emitted light is then photoelectrically detected to produce an image information signal that is electrically processed for generating image information which is recorded as a visible image on a recording medium such as a photosensitive material or displayed as a visible image on a CRT or the like.
The visible image thus produced may be recorded on a recording medium by an image recorder such as an image output laser printer, for example. In the image output laser printer, photographic films stored as a recording material in a magazine are loaded, and taken out one by one by a sheet delivery device such as a suction disk or cup. Thereafter, the film is exposed to a laser beam modulated by an electric signal produced from the stimulable phosphor sheet, for thereby recording an image on the film. The exposed film is then transferred into an automatic developing device and processed thereby to develop the image. The film is thereafter stored in a prescribed place or used for medical diagnosis when required.
When loading the films into the image output laser printer, they must not be exposed to extraneous light as is the case with the conventional radiation image photographing device. Therefore, it is general practice to load the films into the image output laser printer in a dark room, but the efficiency of such a loading process is low.
There is a strong demand for the loading of films under bright conditions such as in an ordinary bright room, and various arrangements have been proposed for loading films in bright environments One such proposal is disclosed in Japanese Laid-Open Utility Model Publication No. 61(1986)-20591, for example.
The disclosed scheme will briefly be described below with reference to FIG. 1 of the accompanying drawings. FIG. 1 shows in cross section a package 2 which can be loaded into a radiation image photographing device through a magazine (not shown). The package 2 comprises a bag 4 and a protective board 6 of paper for protecting films F stored in the bag 4. The bag 4, with the films F and the protective board 6 contained therein, has its opposite ends 4a, 4b closed off.
The protective board 6 has a substantially J-shaped cross-section including a lower panel 6a, an upper panel 6b, and a holder portion 6c. The films F are stored as a stack between the upper and lower panels 6a, 6b. The upper panel 6b is shorter than the lower panel 6b.
After the package 2 has been placed into a radiation image photographing device through a magazine or the like (not shown), the end 4a of the bag 4 is torn open, and then the other end 4b thereof is pulled in the direction of the arrow to remove the bag 4. The films F are now loaded in the radiation image photographing device, and will be delivered or fed by a suction cup 8 of a film delivery mechanism for recording images thereon.
The radiation image photographing device has a large depth since the films are loaded and delivered in the same direction in the radiation image photographing device. Where the radiation image photographing device is located in a small room, any remaining space available in that room cannot effectively be utilized for other purpose.
To allow the radiation image photographing device to be appropriately installed in a small space, the depth of the device may be reduced by feeding the films from the package in a direction substantially normal to the direction in which the films have been loaded. In this arrangement, the bag 4 of the conventional package 2 is pulled in a direction parallel to the holder portion 6c of the protective board 6. Therefore, upon such removal of the bag 4, the stored films F may also be removed with the bag 4, or the films F and the bag 4 may not smoothly be separated from each other.
If the holder portion 6c is positioned in the direction in which the bag 4 is removed for the purpose of preventing the films F from moving with the bag 4 upon its removal, the stacked films F will not effectively be fanned at the time of feeding the films F, and it is highly likely for a number of films F to be delivered at a time. More specifically, when a film F is to be fed, it is fanned so as to be separated from the film stack so that two or more films F will not be delivered together. With the protective board 6 arranged as shown, the film F to be fed will engage a side edge of the upper panel 6b of the protective board 6 and then fall down. Therefore, the film F cannot smoothly be delivered.
In the conventional arrangement, the protective board 6 has a hole 7 for preventing the suction cup 8 from continuously attracting the protective board 6 and hence from damaging a vacuum pump in the suction system connected to the suction cup 8, after all of the films F have been delivered out by the suction cup 8.
The projective sheet 6 is normally in the form of a hard sheet such as a highly rigid paper board or a synthetic resin sheet. Therefore, stored films F tend to have a pressure mark resulting from the profile of the hole 7. Moreover, the moisture or gas contained in the protective board 6 is apt to develop a fog on the films F. Fibers detached from the surface of the protective board 6 or the peripheral wall surface of the hole 7 are liable to be attached to the films F, presenting an obstacle to good image development or producing a spot on the developed image.
The films F protected by the protective board 6 are also caused to have pressure marks by the hole 7 during shipment thereof.
Where the protective board 6 is made of paper board such as unbleached kraft paper, for example, a harmful substance or gas discharged from the unbleached kraft paper tends to adversely affect the films F held against the protective board 6. In case the protective board 6 is made of bleached kraft paper, no harmful gas is emitted, but the moisture in the bleached kraft paper is likely to develop a fog on the films F in contact therewith or vary the sensitivity of the films F. Further, pressure marks are also impressed on the films F when they are under load.